﻿// Copyright 2004-2012 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#region 导入名称空间

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.Serialization.Formatters.Binary;
using LightWork.DynamicProxy.Generators;

#endregion

namespace LightWork.DynamicProxy.Serialization
{
    /// <summary>
    /// Applied to the assemblies saved by <see cref="ModuleScope" /> in order to persist the cache data included in the
    /// persisted assembly.
    /// </summary>
    [AttributeUsage(AttributeTargets.Assembly)]
    [CLSCompliant(false)]
    public class CacheMappingsAttribute : Attribute
    {
        private static readonly ConstructorInfo constructor =
            typeof(CacheMappingsAttribute).GetConstructor(new[] {typeof(byte[])});

        public CacheMappingsAttribute(byte[] serializedCacheMappings)
        {
            SerializedCacheMappings = serializedCacheMappings;
        }

        public byte[] SerializedCacheMappings { get; }

        public Dictionary<CacheKey, string> GetDeserializedMappings()
        {
            using (var stream = new MemoryStream(SerializedCacheMappings))
            {
                var formatter = new BinaryFormatter();
                return (Dictionary<CacheKey, string>) formatter.Deserialize(stream);
            }
        }

        public static void ApplyTo(AssemblyBuilder assemblyBuilder, Dictionary<CacheKey, string> mappings)
        {
            using (var stream = new MemoryStream())
            {
                var formatter = new BinaryFormatter();
                formatter.Serialize(stream, mappings);
                var bytes = stream.ToArray();
                var attributeBuilder = new CustomAttributeBuilder(constructor, new object[] {bytes});
                assemblyBuilder.SetCustomAttribute(attributeBuilder);
            }
        }
    }
}